#### GATE Exam Questions

1

Group symbols assigned to silty sand and clayey sand are respectively

A. SS and CS
B. SM and CS
C. SM and SC
D. MS and CS

2

In a BOD test using 5% dilution of the sample (15 ML of sample and 285 mL of dilution water), dissolved oxygen values for the sample and dilution water blank bottles after five days incubation at 20^circC were 3.80 and 8.80 mg/L. respectively. Dissolved oxygen originally present in the undiluted sample was 0.80 mg/L. The 5-day 20^circC BOD of the sample is

A. 116 mg/L
B. 108 mg/L
C. 100 mg/L
D. 92 Mg/L

3

A footing 2 m x 1 m exerts a uniform pressure of 150 kN/m2 on the soil. Assuming a load dispersion of 2 vertical to 1 horizontal the average vertical stress (kN/m2) at 1.0 m below the footing is

A. 50
B. 75
C. 80
D. 100

4

Two completely penetrating wells are located L (in metres) apart, in homogeneous confined aquifer. The drawdown measured at the mid point between the two wells (at a distance of 0.5 L from both the wells) is 2.0 m when only the first well is being pumped at the steady rate of Q1 m3/sec. When both the wells are being pumped at identical steady rate of Q2 m3/sec, the drawdown measured at the same location is 8, 0 m. It may be assumed that the drawdown at the wells always remains at 10.0 m when being pumped and the radius of influence is larger than 0.5 L Q1/Q2 is equal to

A. 8/5
B. 4/3
C. 5/8
D. (L/2)

5

Flow at critical depth takes place in an open channel When

A. for a given specific energy, discharge is maximum
B. for a given discharge, specific energy is maximum
C. discharge is minimum for a given specific energy
D. discharge is maximum for a given specific force